| 1. |
- Jacobsson, Jesper, 1984-, et al.
(författare)
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Extending the Compositional Space of Mixed Lead Halide Perovskites by Cs, Rb, K, and Na Doping
- 2018
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Ingår i: The Journal of Physical Chemistry C. - : American Chemical Society (ACS). - 1932-7447 .- 1932-7455. ; 122:25, s. 13548-13557
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Tidskriftsartikel (refereegranskat)abstract
- A trend in high performing lead halide perovskite solar cell devices has been increasing compositional complexity by successively introducing more elements, dopants, and additives into the structure; and some of the latest top efficiencies have been achieved with a quadruple cation mixed halide perovskite Cs(x)FA(y)MA(z)Rb(1-x-y-z)PbBr(q)I(3-9). This paper continues this trend by exploring doping of mixed lead halide perovskites, FA(0.83)MA(0.17)PbBr(0.51)I(2.49), with an extended set of alkali cations, i.e., Cs+, Rb+, K+, and Na+, as well as combinations of them. The doped perovskites were investigated with X-ray diffraction, energy-dispersive X-ray spectroscopy, scanning electron microscopy, hard X-ray photoelectron spectroscopy, UV-vis, steady state fluorescence, and ultrafast transient absorption spectroscopy. Solar cell devices were made as well. Cs+ can replace the organic cations in the perovskite structure, but Rb+, K+, and Na+ do not appear to do that. Despite this, samples doped with K and Na have substantially longer fluorescence lifetimes, which potentially could be beneficial for device performance.
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| 2. |
- Maccaferri, Nicolò, Dr. 1988-, et al.
(författare)
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Speeding up Nanoscience and Nanotechnology with Ultrafast Plasmonics
- 2020
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Ingår i: Nano Letters. - : American Chemical Society (ACS). - 1530-6984 .- 1530-6992. ; 20:8, s. 5593-5596
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Forskningsöversikt (refereegranskat)abstract
- Surface plasmons are collective oscillations of free electrons at the interface between a conducting material and the dielectric environment. These excitations support the formation of strongly enhanced and confined electromagnetic fields. As well, they display fast dynamics lasting tens of femtoseconds and can lead to a strong nonlinear optical response at the nanoscale. Thus, they represent the perfect tool to drive and control fast optical processes, such as ultrafast optical switching, single photon emission, as well as strong coupling interactions to explore and tailor photochemical reactions. In this Virtual Issue, we gather several important papers published in Nano Letters in the past decade reporting studies on the ultrafast dynamics of surface plasmons.
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| 3. |
- Zhao, Yingbo, et al.
(författare)
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Mesoscopic Constructs of Ordered and Oriented Metal-Organic Frameworks on Plasmonic Silver Nanocrystals
- 2015
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Ingår i: Journal of the American Chemical Society. - : American Chemical Society (ACS). - 0002-7863 .- 1520-5126. ; 137:6, s. 2199-2202
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Tidskriftsartikel (refereegranskat)abstract
- We enclose octahedral silver nanocrystals (Ag NCs) in metal-organic frameworks (MOFs) to make mesoscopic constructs O-h-nano-Ag MOF in which the interface between the Ag and the MOF is pristine and the MOF is ordered (crystalline) and oriented on the Ag NCs. This is achieved by atomic layer deposition of aluminum oxide on Ag NCs and addition of a tetra-topic porphyrin-based linker, 4,4',4?,4 ''-(porphyrin-5,10,15,20-tetrayl)tetrabenzoic acid (H4TCPP), to react with alumina and make MOF [Al-2(OH)2TCPP] enclosures around Ag NCs. Alumina thickness is precisely controlled from 0.1 to 3 nm, thus allowing control of the MOF thickness from 10 to 50 nm. Electron microscopy and grazing angle X-ray diffraction confirm the order and orientation of the MOF by virtue of the porphyrin units being perpendicular to the planes of the Ag. We use surface-enhanced Raman spectroscopy to directly track the metalation process on the porphyrin and map the distribution of the metalated and unmetalated linkers on a single-nanoparticle level.
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